Sustainability overview

Atlantic halibut is widely farmed although in small quantities compared to other species. Unlike salmon and cod, halibut can be farmed in closed tanks as well as in open pens. Choose halibut farmed in closed, shore based production systems such as those used in Scotland, as environmental impacts of production are mitigated. Halibut do have a large dependency on fish to form the majority of their diet, and the fish required to make their feed cannot be assured to come from a sustainable supply. Look for organic farmed fish that can offer this assurance where available. Scottish production is independently addressing this feed concern making it a good choice.

Feed Resources

Criterion Score: -4

Atlantic halibut are fed a commercial diet. The traceability and sourcing of ingredients is unknown, they also require a high percentage of fishmeal and fish oil in their diets.

Environmental Impacts

Criterion Score: 3

Atlantic halibut in Norway are farmed in open net pens and do not require any chemical treatments. Water quality is monitored and there are few instances of escapes or disease outbreaks. Predators are controlled by non-lethal measures.

Fish Health and Welfare

Management

Criterion Score: -1

Overall management requires improvement as although regulations are in place their enforcement and effectiveness is unknown. There is no strategic environmental planning system in place that incorporates halibut production, there is also no independent certification of the species.

Biology

Atlantic halibut, the largest of all flat fishes, is a thick-set, right-eyed (both eyes on the right-hand side of the body) flat fish in the family Pleuronectidae. It is distributed throughout the north Atlantic, particularly Norway, Faroes, Iceland and southern Greenland, but occurs as far south as Maine in north America and the Bay of Biscay in Europe. It can attain a length of 4.7m and more than 300kg, but it is considered slow growing in the wild. Spawning occurs during winter and early spring. Atlantic halibut become sexually mature at 10-14 years, at around 1.4m in length. The oldest recorded halibut has been 55years of age yet models indicate that they could live for nearly 100years! It has been a heavily targeted fishery for more than 100 years and with slow growth rates, high age at maturity and a population doubling time of around 14 years, is highly susceptible to overfishing. IUCN list Atlantic halibut as Endangered (1996) and the species appears on the US National Marine Fisheries Service list of species of concern. Additionally the Project Inshore Phase II Report (2013) noted that under the MSC Risk Based Framework, the species was ranked as the 6th most susceptible species, behind some sharks and rays.

Farmed seafood criterion scoring overview

This system has been developed by the Marine Conservation Society to help businesses and consumers choose the most environmentally
sustainable fish. For full details, please see the full farmed seafood methodology available
here.

Feed Resources

Score

Descriptor

6

No feed inputs required.

-5 to 5

Feed inputs required. Scored according to traceability, sourcing and ingredients.

-6

Unsustainable, untraceable feed with a high fish feed dependency.

Environmental Impact

Score

Descriptor

7

All environmental impacts are mitigated by technology, production method and/or management practices.

For farmed seafood assessments, a 'critical fail' may be triggered and produce a default red rating where juveniles or broodstock are
sourced from wild capture fisheries that are rated 5, red rated, on the Good Fish Guide. For full details, please see the full farmed
seafood methodology available here.

What’s a sustainability range?

Many of the fish listed are caught in different ways and from
different areas of the sea. Some species are caught in a variety
of ways and this range shows that, within a species, some may be
fished sustainably whilst others unsustainably.

To find out the individual ratings for each fish click on the
ratings button next to the image.

Fish that are being assessed are shown with a question mark icon and "No Rating".

This system has been developed by the Marine Conservation
Society to help consumers choose the most environmentally
sustainable fish.

To be assessed

Seafood sources indicated as, 'To be assessed', are those that have not yet been assessed and assigned a rating or are undergoing a period
of review. These include sources previously rated by MCS for which the rating has lapsed, due to changes in the market or MCS priorities and
resources. Given that these sources are not fully assessed, the profile should not be used to infer the current sustainability of the
fishery or farmed species.

If you are interested in the sustainability of this seafood source, please let us know by emailing
ratings@mcsuk.org

Rating 1

Rating 1 (light green) is associated with the most
sustainably produced seafood.

This system has been developed by the Marine Conservation
Society to help consumers choose the most environmentally
sustainable fish.

Rating 3

Rating 3 (yellow) based on available information; these
species should probably not be considered sustainable at
this time. Areas requiring improvement in the current
production may be significant. Eat only occasionally and
check www.goodfishguide.org for specific details.

This system has been developed by the Marine Conservation
Society to help consumers choose the most environmentally
sustainable fish.

Rating 4

Rating 4 (orange) should not be considered sustainable, and
the fish is likely to have significant environmental issues
associated with its production. While it may be from a
deteriorating fishery, it may be one which has improved from
a 5 rating, and positive steps are being taken. However, MCS
would not usually recommend choosing this fish.

This system has been developed by the Marine Conservation
Society to help consumers choose the most environmentally
sustainable fish.

Red Improver

'Red improver' ratings are assigned to seafood sources which have been assessed and rated 5 (red) due to significant environmental concerns
with one or more aspects of their management, capture or production, yet credible efforts to improve these issues have been agreed through a
Fisheries or Aquaculture Improvement Project – a FIP or an AIP - and work is underway. Such projects are normally publicly listed at
www.fisheryprogress.org. MCS wants to encourage environmental improvements in fisheries and fish farms, and so does not recommend avoiding
these sources, as we normally do for seafood rated 5 (red rated).

'Best choice' fish are rated 1 and 2, Fish to Avoid are rated 5.

This system has been developed by the Marine Conservation Society to help businesses and consumers choose the most environmentally
sustainable fish.

Rating 5

Rating 5 (red) is associated with fish to be avoided on the
basis that all or most of the criteria for sustainablilty
have not been met.